(((((((((((Rio)))))))))))))

Just take it one day at a time. Trying to figure out everything about what will happen will just be overwhelming. So it sounds like your dad has a lawyer, and you are wondering if your mom does. That would be something simple to get an answer to (ask her). That can relieve that anxiety. If she doesn't she may have a good reason not to. And you can ask her why. You can also ask her (and your father) questions about how they see things like holidays happening in the future. They might not have thought about it yet, but it is their responsibility as the ones who are getting divorced to think about those things.

While you say that it is an awkward thing to bring up (which I agree) you could do it by when a friend asks you how you are saying, "well right now I'm doing pretty badly (or whatever phrase fits you). They may then ask what is wrong. If they do you can then go on with "I just found out my parents are getting a divorce." That will give you an opening to talk about it. And even if your friends themselves have not had parents who have divorced, they probably know people who's parents have divorced.

If your school provides mental health services you might want to stop in there just to have someone to talk to about this who can be a sounding board through the stress. (assuming you don't already have a T).